Podocarpane and cleistanthane diterpenoids from Strophioblachia glandulosa: structural elucidation, anti-hypertrophy activity and network pharmacology.

In the present investigation, fourteen unprecedented podocarpane diterpenoids strophiolosas A-J, L-N and P (1-10, 12-14, 16), two new cleistanthane derivatives strophiolosas Q-R (17-18), two new dibenzopyroan-ones and one new tetralone strophiolosas S-U (19-21), were isolated from the whole plant of Strophioblachia glandulosa. The structures were elucidated via various spectroscopic analysis, quantum chemistry calculations, and X-ray diffraction. Bioactivity test indicated that compounds 5 and 17 possessed promising anti-cardiac hypertrophy effect in vitro (IC values of 16.

Magic methylation with methyl-containing peroxides.

Methyl groups rank among the most abundant carbon fragments found in natural products and small-molecule pharmaceuticals. The late-stage and environmentally friendly installation of these groups onto biologically active molecules has attracted widespread attention in both industry and academia. In 2008, we published the first use of a methyl radical derived from a peroxide toward a directed transition-metal catalysed C-H methylation.

Palladium-catalysed Tsuji-Trost-type vinyl epoxide cross-coupling with umpolung hydrazones.

Selective functionalisation of synthetically useful vinyl epoxides carbon-carbon (C-C) bond formation has been a major challenge for many years due to its unique inherent chemical reactivity. Non-stabilised carbanions in the form of organometallic reagents have been shown to be robust and versatile reagents in C-C bond formation; however, they are employed in superstoichiometric quantities, require the protection of active functional groups, and generate copious amounts of metallic waste. Therefore, the development of mild carbanion sources as simple alternatives is highly desired.

Intermolecular C-C/C-N σ-bond metathesis enabled by visible light.

Transition-metal-catalyzed double/triple bond metathesis reactions have been well-established due to the ability of transition-metal catalysts to readily interact with π bonds, facilitating the progression of the entire reaction. However, activating σ-bonds to induce σ-bond metathesis is more challenging due to the absence of π bonds and the high bond energy of σ bonds. In this study, we present a novel photo-induced approach that does not rely on transition metals or photosensitizers to drive C-C and C-N σ-bond metathesis reactions.

Photosynthesis of CHOH via oxygen-atom-grafting from CO to CH enabled by AuPd/GaN.

The direct co-conversion of methane and carbon dioxide into valuable chemicals has been a longstanding scientific pursuit for carbon neutrality and combating climate change. Herein, we present a photo-driven chemical process that reforms these two major greenhouse gases together to generate green methanol and CO, two high-valued industrial chemicals. Isotopic labeling and control experiments indicate an oxygen-atom-graft occurs, wherein CO transfers one O into the C-H bond of CH via photo-activated interfacial catalysis with AuPd nanoparticles supported on GaN.

PPh-Promoted Direct Deoxygenation of Epoxides to Alkenes.

Deoxygenation of epoxides into alkenes is one of the most important strategies in organic synthesis, biomass conversions, and medicinal chemistry. Although metal-catalyzed direct deoxygenation provides one of the most commonly encountered protocols for the conversion of epoxides to alkenes, the requirement of expensive catalysts and extra reductants has largely limited their universal applicability. Herein, we report an efficient PPh-promoted metal-free strategy for deoxygenation of epoxides to generate alkene derivatives.

Direct Excitation Strategy for Deacylative Couplings of Ketones.

The homolysis of chemical bonds represents one of the most fundamental reactivities of excited molecules. Historically, it has been exploited to generate radicals under ultraviolet (UV) light irradiation. However, unlike most contemporary radical-generating mechanisms, the direct excitation to homolyze chemical bonds and produce aliphatic carbon-centered radicals under visible light remains rare, especially in metallaphotoredox cross couplings.

Photochemically Driven Peptide Formation in Supersaturated Aerosol Droplets.

The condensation of amino acids into peptides plays a crucial role in protein synthesis and is thus essential for understanding the origins of life. However, the spontaneous formation of peptides from amino acids in bulk aqueous media is energetically unfavorable, posing a challenge for elucidating plausible abiotic mechanisms. In this study, we investigate the formation of amide bonds between amino acids within highly supersaturated aerosol droplets containing dicyandiamide (DCD), a cyanide derivative potentially present on primordial Earth.

Anti-Markovnikov Hydroalkylation of Styrene Derivatives via Hydrazones Catalyzed by Ru-PNP Complex.

A well-defined Ru(II)-PNP complex demonstrated high activity in the anti-Markovnikov hydroalkylation of nonpolarized terminal alkenes via hydrazones. Hydrazone served as a carbanion equivalent to combine with the electrophilic alkene substrate upon activation by the ruthenium catalyst, forming a new C-C bond in a concerted pathway with N as the only theoretical byproduct. Experimental and computational studies suggested the existence of a push-pull interaction that activated the alkene for hydrazone addition and then deduced the mechanism.

Csp-H functionalization of phenols: an effective access route to valuable materials Csp-C bond formation.

In the vast majority of top-selling pharmaceutical and industrial products, phenolic structural motifs are highly prevalent. Non-functionalized simple phenols serve as building blocks in the synthesis of value-added chemicals. It is worth mentioning that lignin, being the largest renewable biomass source of aromatic building blocks in nature, mainly consists of phenolic units, which enable the production of structurally diverse phenols.

Dual role of nitroarenes as electrophiles and arylamine surrogates in Buchwald-Hartwig-type coupling for C-N bond construction.

One of the most widely utilized methods for the construction of C(sp)-N bonds is the transition-metal-catalyzed cross-coupling of aryl halides/boronic acids with amines, known as Ullmann condensation, Buchwald-Hartwig amination, and Chan-Lam coupling. However, aryl halides/boronic acids often require multi-step preparation while generating a large amount of corrosive and toxic waste, making the reaction less attractive. Herein, we present an unprecedented method for the C(sp)-N formation Buchwald-Hartwig-type reactions using synthetically upstream nitroarenes as the sole starting materials, thus eliminating the need for arylhalides and pre-formed arylamines.

Visible-light-induced catalyst-free reductive coupling of aldehydes, ketones and imines with cyanopyridines.

This article introduces a reductive coupling driven by visible-light, facilitating the synthesis of pyridine-substituted alcohols and amines through the reaction of aldehydes, ketones and imines with cyanopyridines. Hantzsch esters serve as reductants in this process, eliminating the need for transition-metals or photosensitizers. The method demonstrates extensive compatibility and finds utility in the late-stage functionalization of both natural and pharmaceutical products, offering a sustainable pathway for the diversification of chemical compounds.

A General Platform for Visible Light Sulfonylation Reactions Enabled by Catalytic Triarylamine EDA Complexes.

Catalytic electron donor-acceptor (EDA) complexes have recently emerged as a powerful and sustainable alternative to iridium- and ruthenium-based photoredox synthetic methods. Yet, these complexes remain underexplored and reliant on the use of meticulously designed acceptors that require previous installation. Herein, we report a novel EDA complex employing tris(4-methoxyphenyl) amine as a catalytic donor for the sulfonylation of alkenes using inexpensive and readily available sulfonyl chlorides.

Palladium nanoparticles on gallium nitride as a Mott-Schottky catalyst for efficient and durable photoactivation of unactivated alkanes.

The direct functionalization of inert C-H bonds has long been a "holy grail" for the chemistry world. In this report, the direct C(sp)-N bond formation of unactivated alkanes is reported with a GaN based Mott-Schottky catalyst under photocatalytic reaction conditions. Long term stability and reaction efficiency (up to 92%) were achieved with this photocatalyst.

Photocatalytic Decarboxylative Minisci Reaction Catalyzed by Palladium-Loaded Gallium Nitride.

The decarboxylative Minisci reaction is a versatile tool for the direct C-H alkylation of heteroarenes, where stoichiometric amounts of oxidants or expensive, precious metal reagents are commonly used. Herein, we reported a photodriven decarboxylative Minisci reaction enabled by a gallium nitride-based heterogeneous photocatalyst under mild conditions. This method can be effectively applied to a broad substrate scope of acids, including primary, secondary, and tertiary carboxylic acids and -heteroarenes effectively.

Mevalonate pathway and male reproductive aging.

Male fertility declines with age. The mevalonate pathway, through which cholesterol and nonsteroidal isoprenoids are synthesized, plays key role in metabolic processes and is an essential pathway for cholesterol production and protein prenylation. Male reproductive aging is accompanied by dramatic changes in the metabolic microenvironment of the testis.

Acceptorless cross-dehydrogenative coupling for C(sp)-H heteroarylation mediated by a heterogeneous GaN/ketone photocatalyst/photosensitizer system.

Alkanes are naturally abundant chemical building blocks that contain plentiful C(sp)-H bonds. While inert, the activation of C(sp)-H via hydrogen atom abstraction (HAT) stages an appealing approach to generate alkyl radicals. However, prevailing shortcomings include the excessive use of oxidants and alkanes that impede scope.

A light-driven selective protocol for on-demand methanol and formic acid syntheses with a recyclable GaN catalyst.

Herein, we present a protocol for the on-demand preparation of methanol and formic acid via selective photo-oxidation of methane with HO and O catalyzed by GaN. The detailed photosyntheses of methanol or formic acid from CH/HO or CH/HO/O are described, respectively. In addition, we provide experimental details for the accurate quantifications of the final gas/liquid products and photoexcited oxygenated radicals.

Triarylamines as catalytic donors in light-mediated electron donor-acceptor complexes.

Recently, photochemistry of Electron Donor-Acceptor (EDA) complexes employing catalytic amounts of electron donors have become of interest as a new methodology in the catalysis field, allowing for decoupling of the electron transfer (ET) from the bond-forming event. However, examples of practical EDA systems in the catalytic regime remain scarce, and their mechanism is not yet well-understood. Herein, we report the discovery of an EDA complex between triarylamines and α-perfluorosulfonylpropiophenone reagents, catalyzing C-H perfluoroalkylation of arenes and heteroarenes under visible light irradiation in pH- and redox-neutral conditions.

Csp -P Bond Formation via Cross-Coupling of Umpolung Carbonyls with Phosphine Halides Catalyzed by Nickel.

A novel method for the formation of Csp -P bonds via the nickel-catalyzed cross-coupling of Umpolung carbonyls and phosphine chlorides is reported herein. This process leads to a series of alkylphosphines, which are characterized as sulfides or borane-phosphine complexes after undergoing further transformation with moderate to good yields. Invaluable free alkylphosphines can be easily obtained by desulfurization or deboration of the products.